Solve day02

day01/src/main.rs

@@ -4,8 +4,8 @@ use std::{
     io::{BufRead, BufReader},
 };
 
-fn either_calories_or_blank(inp: String) -> Option<usize> {
-    inp.parse().ok()
+fn either_calories_or_blank<S: AsRef<str>>(inp: S) -> Option<usize> {
+    inp.as_ref().parse().ok()
 }
 
 #[derive(Default)]

day02/input.test

@@ -0,0 +1,3 @@
+A Y
+B X
+C Z

day02/src/main.rs

@@ -1,3 +1,53 @@
-fn main() {
-    println!("Hello, world!");
+use std::{
+    fs::File,
+    io::{BufRead, BufReader},
+};
+
+// fn calculate_game_score<S: AsRef<str>>(line: S) -> usize {
+//     let line = line.as_ref();
+//     match line {
+//         "A X" => 1 + 3, // Rock    -- Rock
+//         "B X" => 1 + 0, // Paper   -> Rock
+//         "C X" => 1 + 6, // Scissor <- Rock
+//         "A Y" => 2 + 6,
+//         "B Y" => 2 + 3,
+//         "C Y" => 2 + 0,
+//         "A Z" => 3 + 0,
+//         "B Z" => 3 + 6,
+//         "C Z" => 3 + 3,
+//         _ => unreachable!(),
+//     }
+// }
+
+fn calculate_game_score<S: AsRef<str>>(line: S) -> usize {
+    let line = line.as_ref();
+    match line {
+        // Rock -> 1
+        // Paper -> 2
+        // Scissor -> 3
+        "A X" => 3 + 0,
+        "B X" => 1 + 0,
+        "C X" => 2 + 0,
+        "A Y" => 1 + 3,
+        "B Y" => 2 + 3,
+        "C Y" => 3 + 3,
+        "A Z" => 2 + 6,
+        "B Z" => 3 + 6,
+        "C Z" => 1 + 6,
+        _ => unreachable!(),
+    }
+}
+
+fn main() {
+    let file = ::std::env::args()
+        .skip(1)
+        .next()
+        .unwrap_or_else(|| String::from("./input"));
+    let file = BufReader::new(File::open(file).expect("Input file not found"));
+    let sum: usize = file
+        .lines()
+        .map(Result::unwrap)
+        .map(calculate_game_score)
+        .sum();
+    println!("Total score: {sum}");
 }